<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box {
            margin: 0 auto;
        }

        .x {
            width: 300px;
            height: 300px;
            background-color: #ff0000;
        }
        
    </style>
</head>

<body>
    <div class="box">
        <a href="#fload1">1</a>
        <a href="#fload2">2</a>
        <a href="#fload3">3</a>
        <div id="fload1">

        </div>
    </div>
</body>

</html>